1
22
23 package com.liferay.portal.servlet.filters.header;
24
25 import com.liferay.portal.kernel.servlet.HttpHeaders;
26 import com.liferay.portal.kernel.util.FastDateFormatFactoryUtil;
27 import com.liferay.portal.kernel.util.GetterUtil;
28 import com.liferay.portal.kernel.util.HttpUtil;
29 import com.liferay.portal.kernel.util.StringPool;
30 import com.liferay.portal.kernel.util.Validator;
31 import com.liferay.portal.servlet.filters.BasePortalFilter;
32
33 import java.text.Format;
34
35 import java.util.Calendar;
36 import java.util.Enumeration;
37 import java.util.GregorianCalendar;
38 import java.util.Locale;
39 import java.util.Map;
40 import java.util.TimeZone;
41
42 import javax.servlet.FilterChain;
43 import javax.servlet.FilterConfig;
44 import javax.servlet.http.HttpServletRequest;
45 import javax.servlet.http.HttpServletResponse;
46 import javax.servlet.http.HttpSession;
47
48
55 public class HeaderFilter extends BasePortalFilter {
56
57 public void init(FilterConfig filterConfig) {
58 super.init(filterConfig);
59
60 _filterConfig = filterConfig;
61 _dateFormat = FastDateFormatFactoryUtil.getSimpleDateFormat(
62 _DATE_FORMAT, Locale.US, TimeZone.getTimeZone(_TIME_ZONE));
63 }
64
65 protected long getLastModified(HttpServletRequest request) {
66 long lasModified = -1;
67
68 Map<String, String[]> parameterMap = HttpUtil.getParameterMap(
69 request.getQueryString());
70
71 String[] value = parameterMap.get("t");
72
73 if ((value != null) && (value.length > 0)) {
74 lasModified = GetterUtil.getLong(value[0]);
75 }
76
77 return lasModified;
78 }
79
80 protected void processFilter(
81 HttpServletRequest request, HttpServletResponse response,
82 FilterChain filterChain)
83 throws Exception {
84
85 Enumeration<String> enu = _filterConfig.getInitParameterNames();
86
87 while (enu.hasMoreElements()) {
88 String name = enu.nextElement();
89
90 String value = _filterConfig.getInitParameter(name);
91
92 if (name.equals(_EXPIRES) && Validator.isNumber(value)) {
93 int seconds = GetterUtil.getInteger(value);
94
95 Calendar cal = new GregorianCalendar();
96
97 cal.add(Calendar.SECOND, seconds);
98
99 value = _dateFormat.format(cal.getTime());
100 }
101
102
104 boolean addHeader = true;
105
106 if (name.equalsIgnoreCase(HttpHeaders.CACHE_CONTROL)) {
107 HttpSession session = request.getSession(false);
108
109 if ((session == null) || session.isNew()) {
110 addHeader = false;
111 }
112 }
113
114 if (addHeader) {
115 response.addHeader(name, value);
116 }
117 }
118
119 long lastModified = getLastModified(request);
120 long ifModifiedSince = request.getDateHeader(
121 HttpHeaders.IF_MODIFIED_SINCE);
122
123 if (lastModified > 0) {
124 response.setDateHeader(HttpHeaders.LAST_MODIFIED, lastModified);
125
126 if (lastModified <= ifModifiedSince) {
127 response.setDateHeader(
128 HttpHeaders.LAST_MODIFIED, ifModifiedSince);
129 response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
130
131 return;
132 }
133 }
134
135 processFilter(HeaderFilter.class, request, response, filterChain);
136 }
137
138 private static final String _DATE_FORMAT = "EEE, dd MMM yyyy HH:mm:ss z";
139
140 private static final String _EXPIRES = "Expires";
141
142 private static final String _TIME_ZONE = StringPool.UTC;
143
144 private Format _dateFormat;
145 private FilterConfig _filterConfig;
146
147 }